Image reading apparatuses have been widely used heretofore in each of which a document set tray in which a document to be read is placed and an output tray in which a read document is outputted are vertically disposed. Such image reading apparatuses are advantageous in that this disposition realizes small sizes. On the other hand, a user has a difficulty in visually recognizing a document placed on the lower tray.
As a solution to this, for example, Patent Literature 1 discloses a technique for allowing a user to visually recognize a document on the output tray from above the document set tray, in order to prevent a user from leaving a document outputted into the output tray. According the technique, in an image reading apparatus in which the output tray is disposed below the document set tray, a part of the document set tray is made from a transparent material so that a document on the output tray may be visually recognized from above the document set tray.
In use of an image reading apparatus which carries documents of various types which are different in size so as to carry out an image reading process of the documents, a user usually matches a position on the document set tray where a document is placed with a predetermined position corresponding to a size of a document.
For example, Patent Literature 2 discloses the following arrangement. Guide members slidable along a width direction of a document are provided to both ends adjacent in the width direction. The guide members are coupled to each other via a pinion. One guide member moves along the width direction, and accordingly, the other guide member axisymmetrically moves around a center line, along the width direction, of a document set tray.